The following paragraphs are not an admission that anything discussed therein is citable as prior art or part of the general knowledge of people skilled in the art.
U.S. Pat. No. 5,702,090 (Edgman) discloses a plastic fence assembly, particularly adapted for use as residential privacy fencing and the like, comprising plural post members which are formed of hollow extruded plastic and have opposed side walls and end walls intersected by one or more elongated channels. Elongated spacer elements may be inserted in the channels and retained therein by interlocking projections on the spacer elements and recesses formed in the sidewalls of the post channels. The spacer elements support side edges of vertically extending picket members, brackets for horizontally extending center rail members and to position at least one or both of elongated top and bottom rail members of the fence assembly. The top and bottom rail members have elongated slots formed therein for receiving opposite ends of generally planar boardlike picket members. The top and bottom rail members and the spacer members may be cut to length as may the post and picket members to provide fencing of a desirable height and distance between posts.
U.S. Pat. No. 5,988,599 (Forbis) discloses a modular fence system. The system includes fence planks designed for insertion into open channels of upper and lower fence rails. The fence rails are supported in a horizontal orientation between intermittent fence posts, with the fence planks extending vertically between the rails. The planks include resilient protrusions at their upper ends. The protrusions of the planks are designed to fit into internal passages formed in the open channels of the upper fence rail, into engagement with ledges defining the passages, to inhibit inadvertent removal of the planks from the upper rail.
U.S. Pat. No. 6,478,287 (DeSouza) discloses a fence panel constructed from extruded hollow polyvinyl plastic boards. The boards are arranged with vertical end boards and filler boards between the end boards. Three horizontal rails each have a board on each side of the vertical boards with a horizontal filler board between the top rail boards to seal off the upper ends of the vertical boards. All of the boards are secured together with a plastic adhesive without the use of any mechanical fasteners.
U.S. patent application publication 2008/0217598 (Dombroski) discloses a fence assembly that is made up of a plurality of fence sections. Each section is made up of panels with top, bottom and side edges and front and rear surfaces. Slots are spaced from and milled into the panels along one of the sets of edges. A pair of trim extends over and covers the set edges and each trim has projections that snap or slide into the front and rear slots. Alternatively the edges of the panel may be beaded and slid over the slotted side of the trim. The fence sections are coupled pivotably to fence posts such that the panels may pivot, under force of wind, about either their top or bottom end. The panels are restored to generally vertical position by the force of gravity. A counterweight within the fence post linked to the panels can be used to restore panels to their vertical position. In an alternate embodiment, the brackets coupling the panels to the fence posts may slide along the fence posts and the panels bow in response to high winds. The fence panels may include resilient strips along their vertical edges.
U.S. patent application 2008/0023684 (Diamond et al.) discloses a non-metallic fence system that has a singular snap lock mechanism for permitting the easy construction of the fence. It also includes a securing device for fixing a fabric to a fence having a rigid body including at least two prongs therefrom and an open face strut profile capable of receiving the prong therein, wherein the prongs are locked within the open face and the fixture can be removed by twisting 90 degrees.